[DevTools] Added public method for async execution of scripts

Source/core/dom/ScriptExecutionCallback.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ScriptExecutionCallback_h
+#define ScriptExecutionCallback_h
+
+namespace v8 {
+class Value;
+template <class T> class Local;
+}
+
+namespace blink {
+
+template <typename T> class WebVector;
+
+class ScriptExecutionCallback {
+public:
+    ScriptExecutionCallback();
+    virtual ~ScriptExecutionCallback();
+
+    virtual void completed(const WebVector<v8::Local<v8::Value> >&) = 0;
+};
+
+} // namespace blink
+
+#endif // ScriptExecutionCallback_h